Key to switch between vertex, edge and face in Maya bindings
Ctrl+Tab is documented for default Blender layout; there it changes selection mode in Edit mode, in Object mode it activates Weight Paint.
In Maya bindings Ctrl+Tab switches to Weight Paint interaction mode both in Object and Edit modes.
It appears that select mode menu in this case will be on clicking RMB.

I suggest refering to User Preferences > Input window to check for the key bindings there.